What are the treatment options for an adult patient with postnasal drip?

Treatment of Postnasal Drip

Start immediately with a first-generation antihistamine/decongestant combination (such as dexbrompheniramine plus sustained-release pseudoephedrine or azatadine plus sustained-release pseudoephedrine) for a minimum of 3 weeks, as this is the most effective evidence-based first-line treatment for postnasal drip regardless of whether the cause is allergic or non-allergic rhinitis. 1, 2, 3

Initial Treatment Strategy

First-Generation Antihistamine/Decongestant Combination:

• Begin with once-daily dosing at bedtime for the first few days to minimize sedation, then increase to twice-daily therapy after tolerance develops 1, 2, 3
• Most patients will see improvement within days to 2 weeks, though complete resolution may take several weeks to a few months 1, 2
• Continue treatment for a minimum of 3 weeks for chronic cases 2, 3

Common side effects to monitor include:

• Dry mouth and transient dizziness (most common) 1
• More serious effects: insomnia, urinary retention, jitteriness, tachycardia, worsening hypertension, and increased intraocular pressure in glaucoma patients 1
• Monitor blood pressure after initiating decongestant therapy 1

Second-Line and Adjunctive Treatments

If no improvement after 1-2 weeks with antihistamine/decongestant:

Add intranasal corticosteroids (fluticasone 100-200 mcg daily) for a 1-month trial 4, 1, 2, 5

• Intranasal corticosteroids are the most effective monotherapy for allergic rhinitis and also effective for some forms of non-allergic rhinitis 2, 3
• Maximum effect may take several days to develop 5

Nasal saline irrigation can be added as adjunctive therapy 4

• Buffered hypertonic (3%-5%) saline irrigation showed modest benefit in clinical trials 4
• High-volume irrigation (150 mL) improves outcomes through mechanical removal of mucus, enhanced ciliary activity, and disruption of inflammatory mediators 1, 2
• More effective than saline spray because irrigation better expels secretions 1

Alternative for patients with contraindications to decongestants:

Ipratropium bromide nasal spray (42 mcg per spray, 2 sprays per nostril 4 times daily) 1, 2, 3

• Provides anticholinergic drying effects without systemic cardiovascular side effects 1, 3
• Particularly useful for patients with hypertension, cardiac arrhythmia, angina, cerebrovascular disease, bladder neck obstruction, glaucoma, or hyperthyroidism 3
• Effective specifically for reducing rhinorrhea but has no effect on other nasal symptoms 3

Treatment Based on Underlying Cause

For Allergic Rhinitis:

• First-line options include nasal corticosteroids, antihistamines, and/or cromolyn 1
• Oral leukotriene inhibitors can decrease symptoms of allergic rhinitis 1, 2
• Second-generation antihistamines may be more effective for allergic rhinitis than for non-allergic rhinitis 1

For Non-Allergic Rhinitis:

• First-generation antihistamine plus decongestant combination remains first-line 1, 2
• Newer-generation antihistamines are less effective for non-allergic causes 1, 2

For Acute Bacterial Rhinosinusitis (if present):

• Watchful waiting is appropriate for uncomplicated cases with assured follow-up 4, 2
• If antibiotics are prescribed, amoxicillin with or without clavulanate is first-line for 5-10 days 4
• Analgesics, topical intranasal steroids, and/or nasal saline irrigation may be recommended for symptomatic relief 4

For Chronic Sinusitis:

• Minimum of 3 weeks of antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 2, 3
• Combined with 3 weeks of oral antihistamine/decongestant and 5 days of nasal decongestant 2, 3
• Followed by 3 months of intranasal corticosteroids 2, 3

Critical Pitfalls to Avoid

Topical nasal decongestants (oxymetazoline, xylometazoline):

• NEVER use for more than 3-5 consecutive days due to risk of rhinitis medicamentosa (rebound congestion) 4, 1, 2

Antihistamines in non-atopic patients:

• Have no role in symptomatic relief of acute bacterial rhinosinusitis in non-atopic patients 4
• May worsen congestion by drying the nasal mucosa 4
• However, second-generation H1-antagonists can be considered for patients with significant allergic component 4

"Silent" postnasal drip:

• Approximately 20% of patients have no obvious symptoms yet still respond to treatment 1, 2
• Failure to consider this can lead to missed diagnoses 1, 2
• Always give an empiric trial of first-generation antihistamine/decongestant therapy before looking for less common causes 1

Guaifenesin:

• Has limited evidence for efficacy in postnasal drip despite its over-the-counter availability 4, 2
• No evidence regarding effect on symptomatic relief of acute bacterial rhinosinusitis 2

When to Reassess

If symptoms persist after 2 weeks of adequate upper airway treatment:

• Proceed with sequential evaluation for other common causes of chronic cough, including asthma/non-asthmatic eosinophilic bronchitis and gastroesophageal reflux disease (GERD) 1
• Consider sinus imaging (radiographs or CT) if persistent nasal symptoms despite topical therapy 1
• GERD frequently mimics postnasal drip with upper respiratory symptoms, and improvement from GERD treatment may take up to 3 months 1

Maintain all partially effective treatments rather than discontinuing them prematurely, as upper airway cough syndrome, asthma, and GERD together account for approximately 90% of chronic cough cases 1